package com.itheima.Controller;

import com.itheima.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

/**
 * 文件
 */
@Slf4j
@RestController
@RequestMapping("/common")
public class CommonController {

    @Value("${reggie.path}")
    private String basePath;

    /**
     * 文件上传
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file) throws IOException {
        //file是一个临时文件，需要转存到指定位置，负责本次请求完成后临时文件会删除
        //原始文件名
        String originalFilename = file.getOriginalFilename();
        String substring = originalFilename.substring(originalFilename.lastIndexOf("."));

        //使用UUID重新生成文件名，防止文件名重复造成文件覆盖
        String fileName = UUID.randomUUID().toString() + substring;

        //穿件一个目录对象
        File dir=new File(basePath);

        //判断当前目录是否存在
        if(!dir.exists()){
            dir.mkdirs();
        }

        file.transferTo(new File(basePath+fileName));

        return R.success(fileName);
    }

    /**
     *     文件下载
     */

    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){
        try{
            //输入流，通过输入流获取文件内容
            FileInputStream fileInputStream=new FileInputStream(new File(basePath+name));

            //输出流，通过输出流将文件写会浏览器在浏览器展示照片
            ServletOutputStream outputStream=response.getOutputStream();

            response.setContentType("img/jpg");

            int len=0;
            byte[] bytes=new byte[1024];
            while ((len=fileInputStream.read(bytes))!=-1) {
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }

            outputStream.close();
            fileInputStream.close();
        }catch (Exception e){
            e.printStackTrace();
        }
    }
}
